We are developing an animal model for amblyopia research to determine if new approaches for treatment of babies with congenital monocular cataracts are valid. Until recently, unilateral congenital cataracts were considered untreatable because lack of form or pattern vision during the first months of life inevitably resulted in profound, irreversible amblyopia from unbalance visual inputs. Visual recovery may be possible by early removal of unilateral cataracts, prompt correction of the resulting aphakia with continuous wear contact lenses and occlusion of the good eye. However, amblyopia remains an important complication in most cases of early monocular deprivation in sprite of improved treatment methods. Unfortunately, amblyopia treatment is difficult to assess in the clinic due to incomplete medical history, associated abnormalities, inconsistency of amblyopia therapy, difficulty assuring patient follow up, absence of untreated controls and non-standardized tests of visual function. These confounding variables can be overcome by using a carefully controlled animal model. We plan to make newborn monkeys aphakic to simulate as closely as possible the treatment of unilateral congenital cataracts in human babies. Contact lenses comparable to those recently produced commercially for correction of aphakia in human infants will be used in the experimental animals. Occlusion of the good eye will be accomplished by soft occluder lenses. The visual outcome will be measured behaviorally to determine the efficacy of the continuous wear contact lenses as means to prevent amblyopia in the aphakic eye. Nine infant monkeys will be studied. This research is designed to demonstrate the feasibility of continuous wear contact lenses for amblyopia research in infant monkeys and to provide pilot data important for future amblyopia research. Our studies should also produce information relevant to the rehabilitation of cataractous eyes in children.